Durability engineering in all-inorganic CsPbX3 perovskite solar cells: strategies and challenges

All-inorganic cesium (Cs)-based perovskites have been considered as one of the most popular research directions in the community of perovskite photovoltaic devices over the recent years because of their more competitive environmental stability in comparison with the traditional organic-inorganic hybrid perovskite candidates. Since the first attempt for the all-inorganic photovoltaic solar cell in 2014, the recently stabilized device efficiency has exceeded 20% and a large number of relevant researches have been reported. Different optimization strategies, including component replacement, additive, dimension regulation and process modulation, are the conditions to be fulfilled beforehand for the improvement of both stability and efficiency of the inorganic perovskite devices, affording exclusive advantages for application into device architecture. In this review article, the significant advancements of all-inorganic perovskite are systematically discussed, ranging from the materials component and structure to the preparation processing technique. Moreover, we also take several insights into the kinetics for moisture, illumination and thermal stability of the all-inorganic perovskites. We also discuss the promised advantages and shortcomings of each strategy that has been presented in the most recent publications. Finally, we summarize the current challenges and prospects for the future investigation directions of implementing varying strategies to fabricate high-performance photovoltaic devices, promoting their commercial application. • Instability factors and operating mechanism in all-inorganic halide perovskite device are concisely presented. • Promising strategies to stabilize photo-active perovskite phase in different environment stresses are reviewed. • Major advantages and potential challenges in fabricating efficient and stable perovskite device are discussed.